News > August 30, 2007

By Liza Greenspun | News editor

Researchers at the Wake Forest University Baptist Medical Center have discovered that autism may be caused by deficiencies in connections between brain cells within a single region of the brain rather than only between regions, as was previously believed.

Tony Wilson, lead researcher and assistant professor of neurology at the Wake Forest University School of Medicine, explained that the overall findings were that autistic children had a deficit in the left auditory cortex of the brain, but not in the right auditory cortex.

The auditory cortexes are regions of the brain that respond to sound stimulation, Wilson said, adding that the finding was significant in that the deficits were in particular regions of the brain rather than in the overall network.

The results of the tests used in this study were reported in this month’s issue of Biological Psychiatry.

In the study, a group of 10 children or adolescents with autism and another group of 10 without autism listened to a series of clicks occurring every 25 milliseconds for a duration of 500 milliseconds.

There was a significant difference between the two groups in the left hemisphere of the brain, which is the region of the brain that controls language and logic, but there was not a significant discrepancy between the two groups in the right hemisphere of the brain, which controls attention and spatial processing.

“Our results made sense,” Wilson said in a press release.

“Both anecdotal and behavioral evidence suggest children with autism have significantly disturbed brain circuits on the local-level within an individual brain area.

“For example, they tend to restrict their visual gaze to a part of someone’s face, like a nose or an eye, but not the person’s whole face.”

The results also support previous research that found something called long-range connectivity, which shows disconnections between two or more regions of the brain. This particular research shows that the disconnection may actually begin within individual brain regions, called local connectivity.

The magnetoencephalography, or MEG, instrument, which Wilson said looks similar to a 1960s- style hair dryer that fits over the head, measured the brain’s responses to these clicks.

Wilson said that he recently moved to Baptist Medical Center to be the MEG scientist at Wake Forest from the University of Colorado because of the advanced technologies at the university.

“We have one of the world’s best MEG systems,” Wilson said, explaining that the instrument has 275 channels, or sensors which attach to the head in order to measure the magnetic field that is created by brain cell communication.

Only seven to nine of such advanced MEG instruments exist in this country, Wilson said.

Wilson plans on using this machine to expand the research to look at different types of sounds and different regions of the brain, as well as to study the vocal system and the ability of autistic children to watch and imitate hand gestures.

“We’re currently recruiting volunteers,” Wilson said.

Anyone interested in volunteering to help with this study or anything should call (336) 716-8694.